From: Milan Broz <gmazyland@gmail.com>
To: Alan Stern <stern@rowland.harvard.edu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: usb-storage: how to extend quirks flags to 64bit?
Date: Sun, 27 Aug 2023 11:32:05 +0200 [thread overview]
Message-ID: <f9e8acb5-32d5-4a30-859f-d4336a86b31a@gmail.com> (raw)
Hello,
I tried to extend USB storage for the passthrough of Opal
security commands, and some adapters are clearly "not perfect".
I would need to introduce a new quirks flag to turn it off.
Seems that we are already out of quirks flags on 32bit
for usb storage - in usb_usual.h the last entry in mainline is
US_FLAG(SENSE_AFTER_SYNC, 0x80000000)
Adding a new flag will work for 64-bit systems but not
for platforms with 32-bit unsigned long like i686.
How do we allow new flag definitions?
Struct us_data fflags can be made 64bit (defined in
drivers/usb/storage/usb.h), but the major problem is that these
are transferred through the generic driver_info field
defined in linux/mod_devicetable.h as unsigned long).
Making this 64bit is IMO an extensive API change (if even possible).
I guess this is not the way to go.
Could USB maintainers please help to advise what is the correct
solution? I am not familiar with the USB driver model here
and I see no easy way how it can be solved by a trivial static
allocation inside the USB storage driver.
Someone will need a new quirks flag in the future anyway... :)
Thanks,
Milan
next reply other threads:[~2023-08-27 9:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-27 9:32 Milan Broz [this message]
2023-08-27 15:50 ` usb-storage: how to extend quirks flags to 64bit? Alan Stern
2023-08-27 16:45 ` Milan Broz
2023-08-27 18:55 ` Alan Stern
2023-08-30 20:39 ` Milan Broz
2023-08-31 15:54 ` Alan Stern
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f9e8acb5-32d5-4a30-859f-d4336a86b31a@gmail.com \
--to=gmazyland@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=stern@rowland.harvard.edu \
--cc=usb-storage@lists.one-eyed-alien.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).